General help/understanding needed please

[fanno]

Hello

I am not sure what route i need to take here.

i am playing arould with emulator in a rockwell plc. and need a interface for it so i testing out this project.

simple root bariables i think i have the hang on

but when i have to create UDT's i have been using structs.

TMyStructure

• foo
  -baa

i then create the structure as a variable and it seems to be populated corectly.

myvar = TMyStructure(foo...,baa....)

via opc i dont have access to t

myvar.foo and myvar.baa ? as i would expect ?

i have to create a add a variable to the myvar node and then i can get

myvar.foo / myvar.baa

but then i have to wariables that are not reallt the same

SHOULD be using add object instead of structure?

problem i see with using object is that the client just sees a object but not a object of type "TMyStructure"

-Thanks

[oroulet]

first you need to find out if you need a client or a server. From your text over it sounds like you want a client. if you use a client you do not need to create any structure, you just load those from the server using load_data_type_definition().
Look at the examples

[fanno]

Think i am just really bad at explaning it. i appoligize.

To interface with the PLC i am emulering i use this project.

What i am confused about is

BasicObjeect vs Struct (base_object_type.add_object_type vs new_struct)

When i use a struct i can get it to work but new_struct_field is not acessable indivitually in the opc tags.

when using add_object_type with set_modelling_rule(True) i get all the tags as i would expect.

What i am confused/unsure about is weather or not BasicObjeect or Struct is the "correct" / best aprotch to use.

from plc it self (not opcua so it is posible that is a differance): i am not at work so can't retest the structure on a real plc

If i use basic object

if i use struct i can get it to be identical but then i have to add extra variables "manually"
Timer(TIMER struct) value = TIMER (PRE.........)
PRE add_variable to Timer <- value is independed from Timer.Value
ACC add_variable to Timer <- value is independed from Timer.Value
EN add_variable to Timer <- value is independed from Timer.Value
DN add_variable to Timer <- value is independed from Timer.Value
TT add_variable to Timer <- value is independed from Timer.Value

This then shows in the opcua tags as i would "expect" i am new to all of this so it is posible am just missing something.

side question to basic object.

is it correct that they have 0 here instead of 2 ?

[fanno]

Figured out it was ofcause user error =) i did not add idx when creeating the varuiables on the object.

        var = await mycustomobj_type.add_variable(
            self.__idx, field.name, 0, field.type
        )  # demonstrates instantiate
        await var.set_writable()

if i create base objects with another base object inside it.

test2 = await self.__server.nodes.base_object_type.add_object_type(self.__idx, "test2")
  var = await test2 .add_variable(
      self.__idx, "foo", 0, xxxxx
  )
  await var.set_modelling_rule(True)
await test2 .set_modelling_rule(True)

test1 = await self.__server.nodes.base_object_type.add_object_type(self.__idx, "test1")
  var = await test1.add_variable(
      self.__idx, "baa", 0, xxxxx
  )
  await var.set_modelling_rule(True)
  type_nodeid = (await self.__server.nodes.base_object_type.get_child([f"{self.__idx}:test2"])).nodeid
  var = await mycustomobj_type.add_object(self.__idx, f"test2OBJ", type_nodeid)
  await var .set_modelling_rule(True)
await test1 .set_modelling_rule(True)

type_nodeid = (await self.__server.nodes.base_object_type.get_child([f"{self.__idx}:test2"])).nodeid
var = await test1.add_object(self.__idx, f"test2", type_nodeid)

this seems to results in:
creating the new instance:

type_nodeid = (await self.__server.nodes.base_object_type.get_child([f"{self.__idx}:test1])).nodeid
newvar = await self.__folder.add_object(self.__idx, f"test1", type_nodeid)

newvar

• foo
• test2OBJ
• • baa <-------- MISSING ????

the test2 object is not "filled out" amy i doing anything wrong ?